Saturday, April 24, 2010

The first stage to planking the deck is to fit the false deck to the frame. The false deck is usually made from 1mm plywood and will need to be slightly adjusted for the various bulkhead notches if supplied with your kit. Mark the centre line on the deck from bow to stern ensuring that it is lined up squarely with the false keel and that the bulkheads fit through the notches on the false deck. This fit should be neither snug nor loose. The false deck will allow the deck planking to fit easier and lie flatter and more evenly.

The false deck is cambered from the midline to both the starboard and port sides. The amount of camber is usually shown on the waterline drawing that comes with the kit the dimensions of which should be marked by the builder on the bulkheads as a guide. If the plans do not indicate the camber, the general rule is ¼” rise to every foot. Thus in our 1:48 example from the last article where the breadth (beam) is 56 feet, the rise would be 13/32” or 10mm from the centre line to the edge of either the port side or starboard side. Make sure that the sheer plan (length) matches the body plan (depth) and remember that deck curvatures do not always follow the same curvature of the hull sheer exactly. This is because the stern of the ship sits lower in the water than the bow. The level mid point between the stern and the bow is about ¾ of the length of the ship between the stern and the bow. If the plans do not match make adjustments or else fittings like cannons will not sit properly on the deck (cannons should be pointing slightly down). You should also measure the distance from the waterline to the top of the false deck to ensure accuracy with the hull. If need be you can soak the false deck in warm water or warm water with ammonia in order to get the rough curvature that you need. Remember when soaking wood, you should only use warm water and leave the piece in the water for no more than 15 minutes. This way the cells of the wood will be pliable but not broken down.

Once you are happy with the camber of the false deck, make sure that it fits snuggly up to the false keel adjacent to the sternpost or rudder post. Using wood glue and pins adhere the false deck to the bulkheads. Once the false deck is firmly in place, mark and cut out the openings previously marked for the masts, hatches, gratings and companion ways. It is better to do this after the false deck is in place because of the camber of the deck.

Now you are ready to apply planking to the false deck. The decks were usually light coloured. The width of the plank for our 18th Century model is between 8 inches and 14 inches scaled to on average 5.82mm however not all deck planks on a ship are of equal width so any width between 4.23mm and 7.41mm would be acceptable. The thickness of the planking varied from deck to deck. The lower decks were up to 4” thick (2.12mm) and the upper decks 3” thick (1.59mm.) Remember that the length of the board should not exceed 5.5” (140mm).

The deck strakes (planks) were joggled, especially at the rounded edges close to the bow. The end of the plank equals 1/3 of the plank width and the length of the snipe is equal to not less than twice the width of the plank. As far as plank shift is concerned, there are three, four and for French ship, five, plank shifts. As an example, this means that there would be four planks shifted equally between the first and fifth planks in a four plank shift arrangement. It’s helpful to create a cutting jig to ensure that all of the planks are cut evenly and at the correct length. You can also use this jig for the nail pattern.

JOGGLING SNIPE PLANK SHIFT

On a full size ship a gap of 3/8 “ wide (.2mm scaled) was left between the deck planks both lengthwise and at the butt ends to suit the caulking iron. Decks were nailed down next and then caulked with oakum (a mixture of animal hair, sphagnum moss or hemp and tar) and the seam was paid with pitch. There are a number of ways so simulate the tar lines. Depending on the method you use, tar lines should be applied prior to fastening the deck planks onto the false deck.

• Black thread can be glued between the boards.

• Another method is to darken the edges with a marking pen, which you would have to test to be sure the pen does not bleed into the wood and give you a fuzzy line.

• Another method is to use a soft black lead pencil and darken the edges. With the use of a pencil the caulk lines will not be perfectly even and will tend to fade in and out. This does give a realistic appearance.

• By standing the planks on edge and gluing them to a sheet of black paper then cutting them apart will give you a perfectly even caulk seam.

• To produce a subtle appearance simply space the planks ever so slightly apart and allow the glue to ooze up between the planks. You can leave the gap and allow it to fill in with whatever finish (stain, urethane or paint) you intend on using or wipe the seams with a mixture of colored glue, or fill the seams with a graphite paste mixture (used for leak proofing gasket joints). It is a little difficult to maintain an even gap between the planking because as the planks are glued to the hull they require clamping which may cause the planks to shift.

• You can also use black grout as long as your planking material is hardwood.

The nailing or tree nailing pattern depends on the width of the plank The traditional method for adding treenails is to use bamboo strips or hardwood dowels pulled through a draw plate to form the nail. Alternatives would be to use the bristles from paint brushes, whisk brooms, push brooms, wall paper brushes or anything with bristles. Materials composed of copper, brass or silver wire or plastic rods available in many sizes and can be applied by hand or spring loaded nailing tools. Once you form the tree nails, drill holes in the deck planks in the pattern you choose then glue the nails in place. Once complete, give the deck surface a light sanding.

Once you are happy with the deck, it should be sealed either with paint, stain or urethane. If you use urethane, remember to dilute the first two coats by 30% with a thinner (70/30 mix) and apply the third coat full strength.